Peripheral /(?)/

Pe·riph·er·al

Peripheral

a.
  1. Of or pertaining to a periphery; constituting a periphery; peripheric.
  2. External; away from the center; on or near the surface; as, the peripheral portion of the nervous system. (Anat.)
  3. Pertaining to minor, unimportant, superficial, or irrelevant aspects of the matter in question; as, peripheral isssues are dealt with in the appendix.